Many types of vehicles, such as airplanes, ships, and trucks, are used to transport cargo from one location to another. Cargo must be loaded onto these vehicles at an origin location and removed therefrom at a destination location. Due to the size of the vehicles used, it is often necessary to park them some distance from the location where the cargo is stored at the origin or destination and to carry the cargo between the vehicle and the storage location.
This problem is particularly acute at airports where baggage must be moved from large aircraft to a baggage claim or storage area inside a terminal. Typically, baggage is unloaded from the hold of an aircraft by hand, placed onto a truck or trailer, and driven to an entrance in the terminal. From there it is unloaded from the truck onto a conveyor belt or onto an automated guided vehicle (AGV) and taken to the baggage claim or to a storage area. Baggage to be loaded aboard the plane is brought from within the terminal on a conveyor or an AGV, transferred to a truck or trailer, driven to the aircraft, and unloaded from the truck and placed into the aircraft.
Sometimes AGV's are used to transport baggage outside of a terminal. However, AGV's must generally follow well defined paths. When these paths are defined by rails, the rails cannot be run too close to an aircraft's gate approach without interfering with the free movement of the aircraft. When the paths are defined by reference markers, the AGV's are prone to drifting off course and could collide with and damage a plane. Furthermore, many different aircraft will use a given gate, and each of these aircraft will be positioned in a different manner when it arrives at the gate. The cargo doors of different aircraft are also located in a variety of different places. It is not practicable to program an AGV to arrive in exactly the right position for unloading from the various cargo doors of each of these aircraft, especially when the exact position and angle of the aircraft at the gate is unpredictable. Therefore, human operators are used to guide trucks up to the cargo hold of an aircraft and to drive these trucks away from the aircraft to a location where the baggage can be unloaded onto an automated baggage handling system. This need to manually transfer baggage from one transport device to another slows down the loading and unloading operations, increases the labor costs associated with baggage handling, and increases the risk that a bag will be misdirected and not arrive at the proper destination.